Spring bed bottom



R W. MARQUARDT SPRING BED BOTTOM Filed Deo. 6, 1934 mm f . O OO C" /ATTORNEYS Patented Oct. 5, 1937 UNED STATES PATENT GFFICE 1 Claim.

This invention relates to improvements in spring bed bottoms.

It is the primary object of the invention to minimize the recoil or reaction shock or bounce, of the coil springs of a bed bottom. It is my purpose to accomplish this result by the provision of a fully floating base of specialdesign upon which the coil springs are carried. It is the ordinary practice in the manufacture of coil spring bed bottoms, to support the coil springs upon members which are rigidly tight to the frame which rests on the bedstead. I am aware of the fact that in some instances furniture seats have been manufactured in which a sub-frame support for coil springs has been yieldably connected with the main frame along one margin. The purpose of such an arrangement in an upholstered seat is substantially diflierent from the present purposes of this invention, and the present structure is distinct in that the sub-frame on which the coil springs are carried is yieldably supported along both margins by helical springs and is entirely free of the main frame at its ends.

It is a further object of the invention to eliminate sway in a structure of this kind by suitable disposition of the helical springs rby which the sub-frame is floated from the main frame.

In the drawing:

Figure l is a plane view ofk a bed bottom embodying the present invention, some of the supporting helicals being illustrated in full and others being diagrammatically indicated.

Figure 2 is an enlarged detail view taken in section transversely through a fragment of the main frame and supporting frame.

Like parts are identified by the same reference characters throughout the several views.

'I'he spring bed bottom of the present invention comprises three frames of generally rectangular form with rounded corners. There is a main frame at 3, a floating sub-frame at 4, and a top marginal frame at 5. Frame members 3 and 4 are preferably made of angle iron to be substantially rigid throughout, while the frame 5 may comprise a rod or heavy wire in accord-V ance with usual practice.

The strap iron supports 5 for the coil springs 1 are of conventional form except that their ends are anchored to the iioating sub-frame 4 instead of being connected to the main frame 3. The coil springs 8 around the outside of the bed bottomY are identical with coil springs 'l except that they are slightly shorter. They may be mounted directly on the iioating sub-frame 4. The tops of the coil springs 8 are connected with the marginal frame 5, and the tops of the coil springs 'l and are connected in a conventional manner by crossed helicals 9 to provide a supporting fabric for a mattress.

(c1. `snare) 'I'he sub-frame 4 is supported from the main frame 3 by two lateral series of helicals Ill. It will be noted that these helicals are not parallel to the transverse center line of the spring, but are all set at a slight angle toward the nearest end thereof. No helicals whatever need be used between the ends of the frame members 3 and 4, and their omission is preferred. The disclosed arrangement of the helical springs minimizes any tendency of the oating structure to sway longitudinally of the bed bottom.

In a bed bottom having a floating support for its coil springs there is a pronounced tendency to eliminate the bounce or throw which is characteristic of many coil. spring bed bottoms. When a coil spring is compressed, its reaction is obviously equal to the compressive force. If one of its ends is xed on a rigid frame, the reaction can occur only in the free end. In the present device the sub-frame is floated and the reaction of the several coil springs may occur in the lower ends of these springs to reduce greatly the shock which would otherwise be produced in the upper ends thereof. In addition, the presence of the helicals which float the sub-frame tends to absorb the initial shock Which would otherwise be absorbed entirely by the coil springs. The result is to provide a spring structure which is exceptionally well adapted to bed bottom use Ymay be employed for upholstery purposes where the peculiar advantages of the present construction are required, and where the floating movement may be accommodated.

I claim:

A spring bed bottom comprising a main frame having sides and ends, a sub-frame having corresponding sides and ends closely spaced within those of the main frame in approximately the same plane, a marginal frame having sides and ends spaced above those of the main frame, a set of coil springs mounted on the sides and ends of the sub-frame and having their top coils respectively connected with the marginal frame, said marginal frame and coil springs being above and substantially wholly free of said main frame, a set of cross supports carried by the sub-frame, coil springs mounted on said supports and having their top coils interconnected with each other and with the top coils of the coil springs first mentioned, and two series of nearly horizontal helical springs connecting the corresponding sides of the sub-frame and main frame, the ends of the sub-frame being free, and the coil springs along each of the sides of the sub-frame being convergent toward the transverse center line pf the sub-frame.

REINHOLD W. MARQUARDT. 

